Apparatus for jarring well pipe



Nov. 4, 1958 K. E. WAGGENER 2,353,893

APPARATUS FOR JARRING WELL PIPE .Filed Sept. 18, 1956 INVEN TOR. (EA/Mira E hdvanwie :wihoist 2,858,893 Patented Nov. 4, 1958 APPARATUS FOR JARRIN G WELL PIPE Kenneth E. Waggener, Brea, Calif.

Application September '18, 1956, Serial No. 610,586

4 Claims. (Cl.166-"178) This invention relates to an improved method and apparatus for dislodging a drill pipe string stuck or held against normal movement in a well bore.

A major problem encountered in oil well drilling or operating is that of having the pipe string become stuck or lodged in the Well bore. Oftentimes in a drilling operation the side walls of the well bore will cave in to wedge the drilling tool or pipe string against the wall of the well bore and under normal manipulation it is then impossible to advance or retract the pipe string in the well bore. Also, under normal operations, it oftentimes occurs that in a packing oft operation that the packing tool will not come free from the well bore walls when it is so desired, again preventing any longitudinal motion of the pipe string in the well.

To overcome such sticking in the above cases, or any other times in which the pipe string becomes lodged in the well bore, jar tools are used in the pipe string whereby sharp shocks may be transmitted to the stock object to dislodge it from its tightly wedged position. However, if a jar tool had not been inserted in the drill pipe prior to sticking, it is necessary to remove the unstuck pipe and insert a jar and recouple 'the pipe string. The same operation would be necessary if the pipe string becomes stuck in the well bore above a jar inserted in the pipe string. The necessity for removing the unstuck pipe string from the well bore is costly and time consuming.

It is proposed to carry out a jarring operation from the top of the pipe string, where all of the elements are readily accessible to the operator. As is well known, the drill pipe is elastic to a degree and may be elongated by applying an upward tensioned force to the upper end of the pipe string. If, after elongation, the pipe string is abruptly released, the pipe string will contract and the full weight of the pipe string will be applied to the stuck portion as the pipe string rebounds from its stretched position. However, in such an operation, it is necessary that the pipe string be released from its tensioned posi tion so that it is allowed to fall freely. If the usual hoisting line is attached to the pipe string and the tensioning is released the hoisting line will follow the con tracting pipe string. The abrupt stop of the drill pipe upon full contraction will either put asevere strain upon the hoisting apparatus if it attempts to stop the paying out hoisting line immediately, or else the hoisting line will continue to pay out after the pipe has contracted and will flay around wildly, endangering life and equipment.

It is proposed to provide a method and apparatus whereby the extensible properties of the drill pipe may be utilized, by upwardly tensioning the pipe string to cause elongation thereof, and then clamping and holding the pipe string in its elongated position, whereby the ing apparatus may be removed from the pipe string, lse enough slack be put in the hoisting line so that t ng will impede the pipe string in its course of down mhontraction. The pipe string is then released from ibported elongated position and allowed to freely contract to its unstressed position to deliver the jarring blow to the stuck portion of pipe. The danger of flaying hoisting line and danger to life and equipment is thus overcome.

It is an object of this invention to provide a method and apparatus whereby a drill pipe lodged against normal movement in a well bore may be jarred loose by applying tensioning forces to the upper end of the drill pipe, the drill pipe being then clamped and supported against contraction, the tensioning forces removed from the drill pipe, and the drill pipe being then released for unimpeded contracting movement downwardly in the well bore.

Other objects and advantages of the invention Will be apparent in the course of the following detailed description.

In the accompanying drawings forming a part of this application, and in which like numerals are used to designate like parts throughout the same,

Fig. l is an elevational view, partially broken away and partly in schematic of the invention.

Fig. 2 is a cross sectional view taken along lines 22 of Fig. 1.

Fig. 3 is an elevational cross sectional view taken along lines 33 of Fig. 2.

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of my invention, the derrick floor 10 supports a conventional rotary table 11 through which the drill pipe 12 extends from the swivel 13 down through the conventional pressure apparatus 14 mounted on the cellar floor 15 into the well bore 16. A drill bit 17 is shown as connected to the bottom of the drill pipe 12.

A book 18 connects the upper end of swivel 13 to the traveling block 19 of the hoisting works (not shown). A hoisting line 21 passes around the traveling block for raising and lowering the block 19.

Shown as supported on the rotary table is a support means 22 adapted to support collar means 23 fastenable to the drill pipe 12 to enable this invention to be practiced. The support means 22 comprises a pair of arcuate jaws 24 and 26, the jaw 24 being fastened to base plate 27 by means such as bolts 28. The jaw 24 has formed therethrough a hole 29 through which bolt 31 passes, the bolt 31 also passing through hole 32 formed in jaw 26. A nut 33 fastens on one end of bolt 31. A piston head 34 is carried on the other end of bolt 31, with the bolt 31 extending through a hole 36 formed in the piston head 34 and held in place by nut 37. A compression spring 38 mounted around and coaxially with the bolt 31, between the jaws 24 and 26, bias the jaws in opposed directions. As is apparent from the drawings, a second bolt 39 connects the structure in the same manner as bolt 31, on the opposite side of jaws 24 and 26 and piston head 34, with compression spring 33a mounted between the jaws 24 and 26.

A cylindrical piston 40 is formed by providing a cylindrical piston wall member 41 mounted on the piston head 34, as by screw means 42; the piston 40 being adapted to move reciprocally in a circular bore 43 formed in jaw member 24. O-rings 44 mounted on the exterior of the piston 40 prevent fluid leakage between the piston 49 and the bore 43. The piston head 34 is apertured at 46 and screw threaded to receive a fitting 47 on the end of the hydraulic conduit 48.

The other end of hydraulic conduit 48 connects to a conventional three-way valve 49 having one conduit 51 connected through a check valve 52 to pump 53 and another conduit 54 leading toa sump tank 56. Conduit 57 connects the sump tank 56 to the pump 53. The valve 49 is operable to place either the conduit 51 or the conduit 54 in fluid communication with'conduit 48, so that fluid may be pumped from pump 53 into the piston 40, or so that the fluid in piston 40 may be emptied into the sump tank 56.

The collar means 23 has two semi-circular jaw members 61 and 62 adapted to be positioned on opposite sides of a section 63 of the pipe string 12, each jaw member being provided with teeth members 64 and 65 to grip the pipe section 63. Jaw member 61 is provided on its exterior surface with an upper cam surface 66 and a lower cam surface 67, the two cam surfaces inclining outwardly at the middle from the ends of the jaw member. Jaw member 62 is similarly formed. An upper collar member 68 and a lower collar member 69 surround the jar members 61 and 62, the collar members having a screw connection at 71. The upper collar member 68 has an inner cam surface 72 of the same inclination as cam surfaces 66 of jaw members 61 and 62, and the lower collar member 69 has an inner cam surface 73 of the same inclination as cam surfaces 67 of jaw members 61 and 62. As is evident, if the collar members 68 and 69 are screwed together the jaw members will be forced inwardly so that the teeth 64 and 65 will bite into the pipe section 63 to rigidly connect the collar means to the pipe section.

The lower collar member 69 has an annular cam surface 74 extending outwardly and upwardly, the cam surface adapted to be supported by a cooperating surface 75 on the upper surfaces of the arcuate jaws 24 and 26.

The method and manner of operation is as follows: The drill bit 17 and lower end of the drill pipe 12 are shown in Fig. l as being wedged into a stuck position in the bottom 76 of the well bore 16, so that a jarring operation is needed to dislodge the drill pipe. The pipe joint 77 at the upper end of the drill pipe 12 is removed and the support means 22 is placed on the rotary table 11 so that the drill pipe 12 extends between the jaws 24 and 26. The three-way valve 49 is adjusted so as to put conduit 48 in communication with conduit 51, and the pump 53 is operated to force the hydraulic fluid from the sump tank 56 through conduit 57, pump 53, check valve 52, conduit 51, valve 49, and conduit 48 into the piston 40, to cause the support jaws 24 and 26 to move toward each other against the bias of springs 38 and 38a to the position shown in Figs. 2 and 3. The collar means 23 is then placed loosely on the drill pipe and allowed to rest on the annular upper cam surface 75 of support means 22. The pipe joint 77 is recoupled and the traveling block is hoisted by the hoisting line 21 to apply tensioning forces to the upper end of the drill pipe 12, thus causing it to elongate upwardly in the well bore 16. The amount of upward tensioning force may be varied to the amount desired for jarring purposes, with the amount of force preferably below the elastic limit of the drill pipe. An upward force of 100 tons has been used successfully.

With the drill pipe in its elongated position the collar member 23 is tightened onto the drill pipe by screwing the upper aand lower collar members 68 and 69 together, so that the teeth 64 and 65 grip the pipe to prevent relative longitudinal movement between the drill pipe 12 and collar means 23. The hook 18 is either disengaged from the swivel 13, or the hoisting line 21 can be slacked off so as to allow the traveling block 19 to fall freely through a distance at least equal to the amount of elongation produced by stretching the drill pipe 12. The entire weight of the drill pipe is now carried by the collar 23 supported on the support means 22.

The valve 49 is now moved so as to put conduit 48 in communication with conduit 54, which allows the hydraulic fluid in piston 40 to flow into the sump tank 56. Since the downward force exerted by the collar means 23 against the support means 22 produces a horizontal frictional component greater than the force exerted by the springs 38 and 38a it is necessary that the mating surfaces 74 and 75 of the collar means 23 and support means 22 Cir be inclined so that they will slide relatively to each other when the fluid in piston 40 is released. The collar means thus forces the support jaws initially apart and the springs 38 and 38a force the jaws fully apart, allowing the drill pipe and collar to contract uninterruptedly downwardly, thus producing a shock wave upon final contraction thereof which travels downwardly through the drill pipe to the stuck end.

Further jar strokes may be delivered by again tensioning the drill pipe and elongating the pipe to raise the collar 23 above the support means 22 so that the support jaws may again be closed under the collar to support the drill pipe. The jarring operation is continued until the drill pipe is dislodged.

It is to be understood that the form of the invention herewith shown and described, is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or the scope of the attached claims.

Having thus described my invention, I claim:

1. Apparatus for releasing a drill pipe string lodged against normal movement in a well bore comprising means for applying tensioning forces to the upper end of said pipe string to elongate the same, collar means I adapted to surround and grip said pipe string, means for supporting said collar means after said pipe string is elongated to enable said tensioning forces to be removed from said pipe string without a contraction thereof, and means for removing said support from its collar-supporting position to allow said pipe string to contract.

2. Apparatus for delivering a jar to a drill pipe string lodged against normal movement in a well bore comprising means for applying tensioning forces to the upper end of said pipe string to elongate the same, collar means having teeth adapted to grip said pipe string, said collar means having a bottom surface, support means having opposed jaws movable to and from each other and adapted to be spaced around said pipe string, means to move said jaws toward each other whereby the upper surfaces of said jaws support the bottom surface of said collar means, said collar means being supported on said support means and gripped to said pipe string to hold said pipe string in elongated position, whereby said tensioning forces may be removed from said pipe string, and means to move said jaws apart to release said collar means for downward movement to allow said pipe string to contract.

3. Apparatus for delivering a jar to a drill pipestring lodged against normal movement in a well bore comprising means for applying tensioning forces to the upper end of said pipe string to elongate the same, collar means having teeth adapted to grip said pipe string, said collar means having an upwardly and outwardly inclined bottom surface, support means having opposed jaws movable towards and from each other and adapted to be spaced around said pipe string, said opposed jaws having upwardly and outwardly inclined upper supporting surfaces, means to move said jaws toward each other whereby the upper surfaces of said jaws support the bottom surface of said collar means, said collar means being supported on said support means and gripping to said pipe string to hold said pipe string in elongated position whereby said tensioning forces may be removed from said pipe string, and means to move said jaws apart to release said collar means for downward movement to allow said pipe string to contract.

4. Apparatus for delivering a jar to a drill pipe string lodged against normal movement in a well bore comprising means for applying tensioning forces to the upper end of said pipe string to elongate the same, collar means having teeth adapted to grip said pipe string, said collar means having an upwardly and outwardly inclined bottom surface, support means having opposed jaws movable towards and from each other and adapted to be move said jaws apart to release said collar means for downward movement to allow said pipe string to contract.

References Cited in the file of this patent UNITED STATES PATENTS Streda Jan. 29, 1924 Kendrick Dec. 7, 1943 Owens Dec. 1, 1953 

